Dental mixing-slab.



Patented Sept. 10, 1918.

R m W W WITNESS 8 A TTOR/VEYS SAMUEL L. JEFFERIES, OF GAFFNEY, SOUTH CAROLINA.

DENTAL MIXING-SLAB.

Specification of Letters Patent.

Patented Sept. 10, 1918.

Application filed November 1'7, 1917. Serial No. 202,627.

To all whom it may concern:

Be 1t known that I, SAMUEL L. Jnrrnmns, a citlzen of the United States, and a rose dent of Gafl'ney, in the countv of Cherokee and State of South Carolina, have invented certain new and useful Improvements in Dental Mixing-Slabs, of which the following is a specification.

My invention is an improvement in dental mixing slabs, and has for its object to provide a slab especially designed for mixing plastic material, wherein the slab is so arranged that it may be used more than once without the necessity of cleaning the slab, the slab having two or more mixing faces, and wherein means is provided for permitting the slab to be retained at a uniform temperature durin; the operation of mixing.

In the drawings:

Figures 1, 2, 3 and 4 are perspective views of various embodiments of the invention; and

Fig. 5 is a perspective view of one of the closing plugs for the slab.

In the embodiment of the invention shown in Fig. 1 the slab 1, which is of glass or other like material, is in the form of a block having an approximately square cross section. Upon each face of the block and at each end thereof there is provided a rib 2 extending transversely of the block, the said ribs at each end being continuous about the faces of the block. The face of the block between the ribs is the mixing face or recess of the block, and it will be evident that when one face has been used it is only necessary to turn the block and another face is ready for use. Thus four mixing operations may be performed with the same slab before it is necessary to clean the same.

In the embodiment of the invention shown in Fig. 2 the slab 3 has a rectangular cross section, and the upper and lower faces of the block have transverse ribs 4 corresponding to the ribs 2 of Fig. 1. 4

In the embodiment of the invention shown in Fig. 3 the block 5 has the end ribs 6 corresponding to the ribs 2 and, in addition, has a central transverse rib 7 on each face, the said ribs dividing each face of the block into two mixing recesses, namely, one at each side of the rib 7.

In Fig. 4 the block 8, which is similar to the block 3, being rectangular in cross section, has the end ribs 9 and, in addition, has a central transverse rib 10, which divides each face of the block into two mixing recesses.

It is desirable in mixing operations that the temperature of the mass being mixed be retained uniform, and this is difiieult in hot weather. For this purpose each of the blocks 1, 3, 5 and 8 is cored longitudinally at its center, as indicated at 11, 12, 13 and 14, respectively, to provide a cylindrical opening extending the full length of the block. Within this opening may be inserted ice in hot weather or heating means in cold weather, if desired, to retain the block at a uniform temperature during the mixing operation. When ice is used, the plugs 15 shown in Fig. -5 may be used to close the ends of the opening. These plugs are merely rubber stoppers.

It will be obvious that with the blocks shown in Figs. 2 and 4 the openings may be of rectangular cross section or several cylindrical openings may be provided, in order to provide suflicicnt storage space for the ice.

It will be understood that the openings 11, 12, 13 and 1% may extend only part way of the length of the block, that is, the openings may open at only one end of the block, and they may have any desired cross sec tion.

' I claim:

1. A slab comprising a block having a rectangular cross section, and having at each end of eachface a transverse rib to form between the ribs a mixing recess, and having transverse ribs at the center of each face to sub-divide the mixing recesses, each block being cored longitudinally to provide an opening for receiving cooling or heating means to retain the block at a uniform temperature during the mixing operation.

2. A dental mixing slab having a chamber or opening in its interior and communicating with the surface of the slab at one face thereof.

- SAMUEL L. J EFFERIES.

Witnesses:

THos. B. BUTLER, W. L. HALL.

Copies 01 this patent may be obtained for five cents each, by addressing the "Commissioner of Patents.

Washington, D. G. 

